diff --git a/lxc-apps/decidim/image.d/srv/decidim-app/Gemfile b/lxc-apps/decidim/image.d/srv/decidim-app/Gemfile
index 2290be3..2bede1c 100644
--- a/lxc-apps/decidim/image.d/srv/decidim-app/Gemfile
+++ b/lxc-apps/decidim/image.d/srv/decidim-app/Gemfile
@@ -10,7 +10,7 @@ gem "decidim", "0.21.0"
 
 gem "bootsnap", "~> 1.3"
 
-gem "puma", "~> 3.12.2"
+gem "puma", "~> 4.3.3"
 gem "uglifier", "~> 4.1"
 
 gem "faker", "~> 1.9"